What Can Cause Pain In Foot After Injury?

Hi - I have a question about a foot injury.21 Yrs old, F, 5'2", 130 lbs, previous history of small ankle sprains from soccer/volleyball but nothing too serious.I fell down the stairs last night and landed on the outside of my right foot. Couldn't put any weight on the ball of the foot but can hobble around on my heel with some assistance from grabbing onto furniture. Woke up this morning still unable to put weight on it but it doesn't appear to be swollen or bruised in color...how long should I wait to go to the doctor and know if it's more than what a little ice can't fix?